## Development of High Efficient Foam for Refrigerator using new HFC blowing agents Kuninari Araki 1) , Kazuto Uekado 2) and Akihide Katata 3) Representing The JEMA Subsidized Project 1) Hitachi Ltd., 2) Matsushita Refrigeration Co., 3) The Japan Electrical Manufacturers' Association

ABSTRACT Since the end of 1993, we have developed High-Efficiency foam of refrigerator for HCFC

-141 b replacement in the subsidized project by MITI (The Agency of Natural Resources and Energy
. Ministry of International Trade and Industry ). Seven major refrigerator manufacturers in Japan jointed this project and made technical evaluation steps about urethane foam for refrigerators using next generation blowing agents to make High

-Efficiency foams

. The items to be reported are as mentioned below. (1) Research about next generation blowing agents (2) Thermal conductivity of new HFCs' panel foam (3) Cabinet injected test results of new HFCs



### 1. Introduction The Japan Electrical Manufacturers ' Association (JEMA) has started the project subsidized by MITI , for developing next
-generation insulation materials to replace current HCFC blown foam , from December 1993 , as a JEMA Subsidized Project with members from the 7 main refrigerator manufacturers in Japan. This project is aimed at the establishment of post-HCFC technology that can suppress the increase of power consumption in household electric refrigerators / freezers, through the development of next
-generation insulation techniques with high efficiency.When starting development work, the following conditions of selecting nextgeneration insulation technology were settled: 1) Blowing agents shall have zero ODP and small HGWP.

477 

## Development of High Efficient Foam for Refrigerator using new HFC blowing agents

ABSTRACT Kuninari Araki 1) , Kazuto Uekado 2) and Akihide Katata 3) Representing The JEMA Subsidized Project 1) Hitachi Ltd., ,2) Matsushita Refrigeration Co., 3) The Japan Electrical Manufacturers' Association

Since the end of 1993, we have developed High-Efficiency foam of refrigerator for HCFC-141b replacement in the subsidized -project by MITI (The Agency of Natural Resources and Energy, Ministry of International Trade and Industry). Seven major refrigerator manufacturers in Japan jointed this project and made technical evaluation steps about urethane foam for refrigerators using next generation blowing

### agen~~~t**~,l\.,~.** make High-Efficiency foams. The Items to be reported are as mentioned below. (1) Research about next generation blowing agents (2) Thermal conductivity of new HFCs' panel foam (3) Cabinet injected test results of new HFCs
1.lntroductiqn The Japan Electrical Manufacturers' Association (JEMA) has started the project subsidized by MITI, for developing next-generation insulation materials to replace current HCFC blown foam, from December 1993, as a JEMA Subsidized Project with members from the 7 main refrigerator manufacturers in Japan. This project is aimed at the establishment of post-HCFC technology that can suppress the increase of power consumption in household electric refrigerators 

### I freezers, through the development of next-generation insulation techniques with high efficiency. When starti'ng development work, the following conditions of selecting nextgeneration insulation technology were settled:

1) Blowing agents shall have zero ODP and small HGWP.



### 477

### 2) Direct and indirect green

-house effects shall be small.

3) Thermal-insulation performance of new materials shall be equivalent to or better than that of the HCFC

-141 b urethane foam. 4) Blowing agents shall be safe from toxicity etc. Insulation materials shall be safe throughout manufacturing , operating and disposal for appliances.The project organization consists of the JEMA secretariat and the 7 research sublaboratories of the 7 refrigerator manufacturers , that actually carry out practical development work

. A total of about 60 researchers are dispatched from the manufacturers and registered as concurrent JEMA personnel and are jointly working for this program. The 7 refrigerator manufacturers are Sanyo Electric, Sharp, Toshiba,. Hitachi, Fujitsu

-General, Matsushita Refrigeration and Mitsubishi Electric. In addition to these project members, there are 6 Japanese urethane formulation manufacturers and 4 potential blowing agents suppliers that are supporting the project. Furthermore, a steering committee is organized with members from academic, industrial and governmental sectors including public research organizations , and the committee discusses orientation of R&D and judgment of results , to maintain social fairness and public benefits as the project Is subsidized by the government. The project was originally started with a term of 5 years, but has been speeded -up to a goal of 4 years to cope with rapidly changing environmental conditions such as earlier restricting HCFC and ruling of new energy standards on household refrigerators / freezers in Japan.
2. The present features and status of refrigerators in Japan At present in Japan, power consumed by electric refrigerators / freezers occupies about one fourth of the total power consumption in a standard Japanese household. Fig. 1 shows trends of domestic shipment quantities and volume zones for the latest about 20 years

. The main zone is 350 - 450L, and multi-door refrigerators of 3- compartments or more, with different temperature ranges are standard . Typically,

478 2) Direct and indirect green·house effects shall be small. 3) Thermal·insulation performance of new materials shall be equivalentto or better

than that ofthe HCFC·141b urethane foam. 4) Blowing agents shall be safe**fr~m** toxicity etc. Insulation materials shall be safe throughout manufacturing, operating and disposal for·appliances.

The project organization consists ofthe JEMA secretariat and the 7 research sublaboratories of the 7 refrigerator manufacturers, that actually carry out practical development work. A total of about 60 researchers are dispatched from the manufacturers and registered as concurrent JEMA personnel and are jointly working forthis program. The 

### 7. refrigerator manufacturers are Sanyo Electric, Sharp,

,**:~~:** .. ;;},,'**,:,~'(** ',\:' "**'~** Fujltsu-General, Matsushita Refrigeration and Mltsublshl Electric. In addition to these

. , project members, there are 6 Japanese urethane forri1ulation manufacturers and 4 potential blowing agents suppliers that are supporting the project. Furthermore, a steering committee is organized with members from academic, industrial and governmental sectors including public research organizations, and the committee discusses orientation of R&D and judgment of results, to maintain social fairness and public benefits as the project Is subsidized by the government. The projectwas originally started with·a term of 5 years, but has been speeded ·up to a goal of 4 years to cope with rapidly changing environmental conditions such as earlier restricting HCFC and ruling of new energy standards on household refrigerators I freezers in Japan.

2. The present features and status of refrigerators in Japan At present in Japan, power consumed by electric refrigerators I freezers occupies about one fourth of the total power consumption in a standard Japanese household. Fig. 1 shows trends of domestic shipment quantities and volume zones for the latest about 20 years. The main zone is 350 • 450L, and multi·door refrigerators of 3· compartments or more, with different temperature ranges are standard. Typically.



### 478

### there are frozen foods, cold storage, vegetablechamber and icetemperature chc-' controlled at nearly WC. Large refrigerators with 5 or 6

-do or type are also used, incorporating ice-making chamber and bottle, chamber. Multi

### preferred InJapan, door refrigerators are use Japanese like fresh fishes such as sashimi and snal fresh foods, so a refrigerator must be delicately temperature

-controlled and quickly cooled. In addition, foodstuff has been diversified and people prefer more of storage chambers finely sectioned in temperatures. Moreover, Japanese climate is particularly high-temperature and -humidity, so automatic defrosting system is required. Therefore, non-frost, fan-cool systems are dominant. Because of limited space for refrigerators in kitchen in Japanese residential situation, refrigerators with freezing function are normally used from the old times

. Thin wall thickness structures are preferred using high

-performance thermal insulation materials to make effective inner volume maximum. Conventionally in Japan , CFC-12 and CFC-11 were used for refrigerators. Substitutes of these CFC, used now in Japan , include HFC-134a mainly for refrigerant and HCFC

-22 for part of large refrigerators , and as blowing agents, HCFC

-141b is mainly used together with HCFC-22/142b or cyclopentane , joint use of vacuum Insulation panel and urethane foam.


### 3. R&D results acquired so far of the project R&D items so far in the project, besides the examination of urethane insulation

479

## z~.

thousand units 5aXl 

## 1Ir:::

I 

# t**-~** Fig.1 

### PRODUCTION of 

### REFRIGERATORs
111301L- 

## .1 /"":'1\ r-- 

## o121-3Cn 1111-12Ol ,/ ..... 

### / / ".

# ~I I"



# - "- i'.. 

## " 

# -
,/ 

# -- ...... V i- ,/ there are frozen foods, cold storage, vegetable chamber and icetemperature chamber' controlled at nearly O:t. large refrigerators 

### with 

### 5 or Godo ortype are also used, Incorporating 4500 4CXIO 3SOO !XXI 2500 2tXXl 1500 1 coo 500



### or



### ! ice-making chamber and '78 '79 's) '81 '82 '83 '84 '85 '86 '87 '88 '89 '!Il '91 '92 '93 '94 '95 bottle. cham'bar. Multldoor refrigerators are

,.' '<,'**'::<'{:~~~Jii~<;' ";:,y,,~'7'**  

### preferred In Japan, because Japanese like fresh fishes such as 

### sashlml and seasonali:', fresh foods, so a refrigerator must be delicately temperature-controlled and quickly cooled. In addition, foodstuff has been diversified and people prefer more of storage chambers- finely sectioned in temperatures. Moreover, Japanese climate is particularly high-temperature and ·humidlty, so automatic defrosting system Is required. Therefore, non-frost, fan-cool systems are dominant Because of limited space for

. refrigerators In kitchen In Japanese residential situation,' refrigerators with freezing function are normally used from the old times. Thin wall thickness structures are preferred using high-performance thermal Insulation materials to make effective Inner volume maximum. Conventionally in Japan, CFC·12 and CFC·11 were used for refrigerators. Substitutes of these CFC, used now in Japan, include HFC·134a mainly for refrigerant and HCFC·22 for part of large refrigerators, and as blowing agents, HCFC·141b is

. . mainly used together with HCFC·221142b or cyclopentane, loint use of vacuum insulation panel and urethane foam.

3. R&D results acquired so far of the project R&D items so far in the project, besides the examination of urethane insulation


### 479

### technology using new HFCs as a blowing agent, include investigating other chemicals

(HC base blowing agents other than pentane , Fluorolodocarbons etc.) and studying on vacuum insulation systems

. However, the most promising alternative technology has been focused to the urethane foam Insulation technology using new HFCs from, the point of view such as Insulation performance, prospective start timing of mass production bef

ore 2000 and economics etc.. Therefore , the development status of urethane foam technology using new HFCs is reported in the following.


### 3.1 Thermal conductivity of panel foams using HFC blowing agents In Fig. 2, typical four types of new HFCs blown foam are compared with HCFC-141 b 

## 2CONDUCTrVITY of HFCs BLOWN FOAMS

20:0 19.0 18.0 17.0 16.0 15.0 14.0 (mw/m-K) Mun Temp 0/10/24('C) Theemal Conductivity at 10'C

17.8 17.3 17.1 6.9 162 16.7
141b(EX) CP(E*) 245b(B) 236ea(X) 356mff 245ea 

### .and cyclopentane foam;based on champion Kfactor data of panel foams tested so far. Meantemperatures of measurement are 24,10 and VC. Measuring instrument used was an auto lambda meter specified by ASTM C518.

For 241 C, an Anacon

- Instrument was also used. Fig. 3 shows all evaluation results tested in 1995, for two types of blowing agents HFC-236ea and 245fa

. The development of optimum insulation materials for refrigerators was attempted In considering "improvement of thermal insulation performance," "modifying and optimizing other physical properties ," " advancement of easy handling at production lines," etc

. Practically, high-qualities and cost effectiveness are most important in addition to the improvement of insulation properties

. Therefore, other factors were also tested and evaluated in the project, including flowability, viscosity and blending of urethane raw materials , mixing ratios of

480 

# ..

technology using new HFCs as a blowing agent, include investigating other chemicals (HC base blowing agents other than pentane, Fluorolodocarbons etc.) and studying on vacuum insulation systems. However, the most promising alternative technology has

. . been focused to the

## urethan~ foam Insulation technology using new HFCs from- 

# the' point of view such as Insulation performance, prospective start timing of mass production before 2000 and economics etc.. Therefore, the development status of urethane foam technology using new HFCs is reported in the following.

3.1 Theonal conductivity of panel foams using HFC blowing agents In Fig. 2, typical four

### types of new HFCs blownfoam are compared with' HCFC·141b 

# IFlg2 

## lHERMAL CONDUCITVITY

. ofHFCsBLOWNFOAMS

.**lU~~~~-r----r---~---r--~** 19.0 HOIIIIlIl!.ll"r:l 18.0**I---+~ 1'-l1----+-~_-f--f**  1--1-----1**11~ I---H:~~+-~~~**  15.0 15.0 14.0 141b(Ex) CP(EX) 145Ca(B) 236a(X) 356mfr 145ca

For 24'C, an Anacon- Instrumentwas also used. 

# I .and cyclopentane**fQal1l~;.** ,**"<_:~~?~f::r:~",>t;'::,** based· on

## champlo~·;. 

# K=' factor data of panel foams tested so far. Mean temperatures of measurement are 24,10 and O'C. Measuring instrument used was an auto lambda meter specified by ASTM C518.

Fig. 3 shows all evaluation results tested In 1995, for two types of blowing agents HFC-236ea and 245fa. The development of optimum insulation materials for refrigerators was attempted In considering "improvement .of thermal Insulation performance," "modifying and optimizing other physical properties," "advancement of easy handling at production lines," etc. Practically, high-qualities and cost effectiveness are most important in addition to the improvement of insulation properties. Therefore, other factors were also tested and evaluated in the project, including flowability, viscosity and blending of urethane raw materials, mixing ratios of


### 480 

## a

### blowing agent and water, optimizing isocyanate, polyol, surfactants, catalyst, etc. The

formulations A, D and Y in Fig. 3 were aimed particularly at high flowability.
Fig.3 THERMAL CONDUCTIVITY of HFCs BLOWN FOAMS (Panel Data)

20
19
18
17 O E(245fa) o O(245fa) o C(245fa) ® B(245fa) p A(245fa)

16
1s 

### Panel evaluation items,other than thermal condIty and flowabil , lnc lude foam density, cell size, compression strength, dimensional stability, chemical compatibility to inner liner, etc. Compared with the results for 1994, K-factors have been ' reduced and foamed cells have been modified to be more microscopic, along with advancement toward lower density

. However, the authors consider that the data of panel foam are only referential and comprehensive evaluation shall be given according to the result of the injected test to be described later, using refrigerator cabinets.
3.2 Evaluation by cabinet injected test Figs. 4 and 5 show K
-factors of urethane foam as a result of cabinet injected tests, 

### Fig.4 CABINET FOAM TEST RESULTS USING HFC-236ea Thermal Conductivity of HFC-236ea foam vs. Current Foam for blowing agents of HFC236ea and 245fa, respectively. The sizes of refrigerator cabinets used for these tests are classified into 10 types from 89 to 420L, 2-4 multi door type. The numbers of injection holes are 1, 2 or 4. K-factor were measured with all samples cut out of cabinets

481 blowing agent and water, optimizing isocyanate, polyol, surfactants, catalyst, etc. The formulations 

### A. 0 and 

### Y In Fig. 3 were aimed particularly at high flowability.
Fig.

### 3 THERMAL CONDUCTMTY 

### ofHFCs BLOWN FOAMS (panel Data) (mW/m·1C) 20**r-------r---~B~.R~U=U~o~f~23~6=** ••**~rC==Ea=4=5~==)~** 11 I--

___ .BOR

### uta of245fa 

## -=..,..,.++-1 C 0(245f.1) 18 1------1,...-----+-=1

16
Ife life 24"'C MeanT....rc) CC(245f.1)**"Ba45~) OA(245~)**  OY(236.a) IIIX(236•• ) Panel evaluation items, other than thermal conductMty**an~** flowability9 include foam density, cell size, compression strength, dimensional stability, chemical compatibility to inner liner, etc. Compared with the results for 1994, K·factors have been· reduced and foamed cells have been modified to be more microscopic, along 

### with

### advancemeni~~;:(<<·~~~)I toward lower density. However, the authors consider that the data of panel foam-are only referential and comprehensive evaluation shall be given according to the result of the injected testto be described later, using refrigerator cabinets.

3.2 Evaklation by cabinet iniected test Figs. 4 and 5 show K·factors of urethane foam as a result of cabinet injected tests,

.

### r;:===============================~ for blowing agents of HFC· Fig.4 

## CABINET FOAM TEST RESULTS USING HFC-236ea Thermal Conductivity ofHFC·236ea foam vs. Current Foam



### x

y

481 236ea and 245fa, respectively. The sizes of refrigerator cabinets used for these tests are classified into 10 types from 89 to 420L, 2-4 multi door type. The numbers of injection holes are 1. 2 or 4. K-factor were measured with all samples cut out of cabinets

### wall, and mean values were calculated for each blown foam and are compared with



### FIg.6 ENERGY CONSUMPTION TEST RESULTS USING HFC-236ea at 60Hz HFC-236ea Foam vs. Current Foam

X/100L( 2door) X/120L( 2d*or) Y/255L( 1 door) (vs 141 b)

80 

### those of urethane foam using current blowing agents.
Figs. 6 and 7 show resultsof power consumption measurement tests, as compared with refrigerators using the current blowing agents. The boiling points of both 236ea and 245fa are lower than that of 141b, so the flowability of foam raw materials becomes an Important characteristic, on which the following test results were obtained.

236ea foam 

### The boiling point of 236ea is low (6.5t), so the injected mixing materials becomes froth state. If the degree of frothing is excessively high, the flowability decreased, and because the shape of mold cavity of refrigerator was complicated, unfilled portions were left occasionally. Consequently, when using urethane with 236ea, the temperature reduction of raw material was absolutely necessary to keep flowability. The results: New facility that can deal with a low-boiling-point blowing agent must be provided to produce commercial goods in stabilized conditions.

482 wall, and mean values were calculated for each blown foam and are compared with those of urethane foam using Fig.5 

## CABINETFOAM

## TEST· RESULTS ofHFC-24Sfa

. lOS eva.14Ib) 

### I 108 eva.141b)

90 100 

# I

110 120 00

Flg.6 

### ENERGY CONSUMPTIONTEST RESULTS USING HFC-236ea

XllOOL(2door) 114 (vsI4Ib) 

## I Y/255L(ldoor)

### ~=~~~?::::;?=(V=S:;22/?:14=2=b)::7j 90 100 110 120 130 XlI20L(2door)

(S)

236ea foam current blowing agents.
Figs. 6 and 7 show results of power consumption meas
.. urement tests, as compared with refrigerators using the current blowing agents. The boiling points of both 236ea and 245fa are lower than

of foam raw materials becomes
an important characteristic, on which the following test results
were obtained.

The boiling point of 236ea is low (6.5'C), so the injected mixing materials becomes froth state. Ifthe degree offrothing is excessively high, the flowability decreased, and because the shape of mold cavity of refrigerator was complicated, unfilled portions
were left occasionally. Consequently, when using urethane with 236ea, the temperature reduction of raw material was absolutely necessary to keep flowability. The results:
• New facility that can deal with a low-boning-point blowing agent must be provided to produce commercial goods in stabilized conditions.

482

### The urethane was charged into a cabinet in a frothed state, so there were many

froth voids in the foam , and K

-factors were not satisfactory in considering cell size. Measured insulation characteristics were lower than expected according to 

### Fig.7ENERGY CONSUMPTION TEST RESULTS USING HFC-245fa HFC-245fa Foam vs. Cunt Foam A/280U3door) A/420L(3door) B/410U4door) 8/120U2door) C/275U4door) D/255Utdoor) E/417U4dood0 0 WF,

I 103 (v; 141b) 104 (vs 141b) 106 (vs 141b) 105 ( 141b) (vs CP) 106 (vs 22/142b) 106 (vs 141b) 110 120 I

100 W 

### the reason why these frothing, phenomenas are encountered during charge Into cabinets.

Measured K-factors of urethane foam cut out of injected cabinets were 1.04 to 1.14 times those of current material , and the ratio of power consumption with the new material to the current one were 1

.04 to 1

. 14 times as large.

245fa foam The boiling point of the 245fa is 15

.30C, and its handling was revealed to be better than 236ea according to the result of cabinet injection. 40 The chargeability of 245fa urethane was comparatively good

. Violent frothing phenomena when injecting could be prevented by lowering the temperature of the raw material to 10 to 1590. The possibility of using the current facility for mass producing refrigerators with 245fa was confirmed by lowering the temperature of raw material, although chargeability will be slightly lower than the current material. 

### As the temperature of raw material was set lower, reaction was slower and chargeability and cureabiiity were adversely affected. Problems to be solved in the future include compromising of reaction and cureabiiity and how to reduce voids.

483 • The urethane was charged Into a cabinet In a frothed state, so there were many froth voids in the foam, and K·factors were not satisfactory in considering cell size. Measured insulation characteristics were lowerthan expected according to

A/420L(3door)

# 1===*==••

Bl410L(4door)

# ~::=::;:~:~:s Bll2OLC2door) 

## I; the reason 

### why these**frothln~** phenomenas are encountered during charge Into cabinets.

• Measured K-factors of urethane foam cut out of Injected cabinets were 1.04 to 1.14 times those of current material, and the ratio of power consumption with the new material to the current one were 1.04 to 1.14 times as large.

245fafoam The boiling point of the 245fa is 15.3'C, and 

### its handling was revealed to be better than 236ea according to the result of cabinet injection.
• The chargeability of 245fa urethane was comparatively good. Violentfrothing phenomena when injecting could be prevented by lowering the temperature ofthe raw material to 10 to 15'C. The possibility of using the currentfacility for mass producing refrigerators with 245fa was confirmed by lowering the temperature of
raw material, although chargeability will be slightly lowerthan the current material.


### • As the temperature of raw material was set lower, reaction was slower and chargeability and cureability were adversely affected.
• Problems to be solved in thefuture include compromising of reaction and cureability and howto reduce voids.
483

### Measured K-factors of urethane foam of disassembled refrigerators were 0.97 to 1.06 times the current materials, and the ratios of power consumption were 0.97 to 1.06 times as large. Some cabinets were tested by charging through one injection hole on the bottom.

"W type formulation was a s devised to Improve flowability of the raw materials to
assure satisfactory chargeability

. According to the test result of this type cabinets, froth voids could be suppressed, and foam could be more uniform. By this effect, power consumption of the refrigerator using "A" blown foam was more than expected from the data of panel foam. In 1996 s research, further improvements are being Introduced, based on the above results

. We are convinced that considerable Improvement result can be expected.


### 3.3 Coen tibility of HFCs with ABS Inner liner The degrees of chemical-attack aggressiveness by blowing agents to the inner liner material ABS are ranked as follows. CFC-11 < HFC-245fa < HFC-236ea < HCFC - 141b aggressive Further long-term reliability tests will be required from now, but we already have a verification that a low

-cost material cheaper than that for HCFC-141 b can be introduced.
3.4 Evaluation of the physical characteristics of new HFCs In cooperation with public research organizations and universities , the project has been conducting various experiments including the estimate of HGWP, toxicity tests, gas phase thermal conductivity of blowing agent candidates. Fig. 8 shows the status of toxicity tests based on The Chemical Substance Control Law of Japan, so far carried out for new candidates . We would be pleased if these test data could somewhat complement an application data for a fluorine chemical manufacturer when it applies a sub

-stance according to the Law.

484 • Measured K-factors of urethane foam of disassembled refrigerators were 0.97 to 1.06 times the current materials, and the ratios of power consumption were 0.97 to 1.06 times as large.
• Some cabinets were tested by charging through one injection hole on the bottom. 

### "AlB typeformulation was devised to Improveflowabillty ofthe raw materials to auu
...satisfactory chargeablllty. According tothe test result ofthis type cabinets, froth voids could besuppressed, and**foa~** could be more uniform. By this effect, power consumption ofthe refrigerator usinguA" blown foam was more than expected from the data of panel foam.

In 1996's research, further improvements are being Introduced, based on the above results. We are convinced that considerable Improvement result can be expected.

3.3 ComPatibility of H.-Cs with ABS inner liner The degrees of chemical-attack aggressiveness by blowing agents to the inner liner material ABS are ranked as follows. CFC-11 

### < HFC-245fa 

### < HFC-236ea 

### < HCFC -141b
- aggressive Further long-term reliability tests will be required from now, but we already have a verification that a low-costmaterial cheaperthan thatfor HCFC-141 b can be introduced.

3.4 Evaluation ofthe physical characteristics of new HFCs In cooperation with public research organizations and universities, the project has been conducting various experiments including the estimate of HGWP, toxicity tests,· gas phase thermal conductivity of blowing agent candidates. Fig. 8 shows the status of toxicity tests based on The Chemical Substance Control Law ofJapan, so far carried outfor new candidates. We would be pleased ifthese test data could somewhat complement an application data for a fluorine chemical manufacturer when it applies a sub-stance according to the Law.



### 484 

## I

### Gas phase thermal conductivitiy of new blowing agents, were measured in Kobe

Fig

## .8 TOXICITY TEST (For The Chemical Substance Control Law)

Reverse-Mutatiort Assay in Bacteria chromosomal Aberration Test 28-days Repeated Dose Toxicity Test in Mammalian Species Biodegradetion Test Bioaccunnulation Test C•245fa 23 6ca 245ca 365mfc FIC' HTC•245fa 236ea 245ca 365mfe no plan to test in JEMA

_ .. no plan to test in JEMA no plan to test in JEMAA 

### Application for

Assessment of Chemical Substance Control Law



### according to these resu lts.


### 4. Conclusions The above results are summarized as follows. University. Thermal conductivitiy of HFC gases are normally higher than those of CFC and HCFC gases. However, K-factors ofurethane foam are approaching those of the 141b blown 'foam, more closely than expected

(1) As long as the R&D results obtained so far are concerned , the best insulation performance relates to the foam based on HFC

-245fa

. We expect that more improvement of Insulation characteristics for refrigerators could be conducted by modifying formuration. (2) Although the boiling point of HFC

-245fa Is lower than 141 b, the current foaming equipment for refrigerators may also be applicable to the agent without substantial modifications, for mass production of refrigerators. (3) The use of 236ea or 245fa as a blowing agent, will not raise particular problems provided the ABS inner liner materials Is optimized. (4) There are no major problems in the process of evaluating basic physical characteristics of new HFCs as a blowing agent. (5) The insulation technology using new HFC blowing agents may become more Important In the near future , as one of the options for energy conservation with electric refrigerators i freezers.

485 

# -

Gas phase thermal conductivitiy of new blowing agents, were measured in Kobe

, Fig.S 

# TOXICITY TEST (For The Chemical Substance Control Law) 

# I**~MutIWcm** 

# I HFC·24sra 236ea A£ay in Bacteria 24Sca 36SmCc**FIC'~** 

# I Chromosomal 

# I HFC·24SCa 236ea : Abemtion Test 24Sca 36SmCc

.....**~** Application for 2Uays Repeated 

# . Assessment of 

# . Dose Toxicity Test no plan to**tes~** inJEMA : . Chemical 

# ............................. in Mammalian Species no plan to test in JEMA : Substance 

# I B iodegradetionTest 

# I·

..........··....···..**····~** Control Law

. no plan to test in JEMA: 

# IBioaccunnulation Test 

## t
..·······..··········..··**~** according tothese results.

4. Conclusions The above results are summarized as follows. University. Thermal conductivitiy of HFC gases are normally higherthan those of CFC and HCFC gases. However, K·factors of urethane foam are approaching those of the 141b blown 'foam, more closely than expected

(1) As long as the R&D results obtained so far are concerned, the best Insulation performance relates to the foam based on HFC-245fa. We expectthat more Improvement of Insulation characteristics for refrigerators could be conducted by modifying formuration. (2) Although the boiling point of HFC-245fa Is lower than 141b, the currentfoaming equipmentfor refrigerators may also be applicable to the agent without substantial modifications, for mass production of refrigerators. (3) The use of 236ea or 245fa as a blowing agent, will not raise particular problems provided the ASS inner liner materials is optimized. (4) There are no major problems in the process of evaluating basic physical characteristics of new HFCs as a blowing agent. (5) The insulation technology using new HFC blowing agents may become more important in the near future, as one ofthe options for energy conservation with electric refrigerators 

### I freezers.



### 485

### 5. View to the future

The project subsidized by MITI for developing HCFC-free, high-performance insulation technology for refrigerators, started from 1993 , will be finished at the end of March 1997, and after that, the industry will continue developing toward the practical goal without a governmental subsidy. Among the development results obtained in 1996 's research, successful improvements other than those presented above are acknowledged. We would like to continue exchanging technical Information with AHAM and ITAC also in the future, and to lead the new HFC blowing technology, currently one of the most hopeful substitute technologies , to an established mass-production technology. We also ;wish that related industrial associations such as construction fields will also consider to practically apply this technology.

486 5. View to the futur! The project subsidized by MITI for developing HCFC-free, high-performance insulation technology for refrigerators, started from 1993, will be finished at the end of March 1997. and after that, the industry will continue developing toward the practical goal without a governmental subsidy. Among the development results obtained in 1996's research, successful improvements otherthan those presented above are acknowledged. We would like to continue exchanging technical information with AHAM and ITAC also in the future, and to lead the new HFC blowing technology. currently one of the most hopeful substitute technologies, to an established mass-production technology. We also ,wish that related industrial associations such as construction fields will also .,< considerto practically applythis technology.



### 486 Q